Conventionally, in a light-emitting element manufacturing process, a functional layer such as a light-emitting layer, a hole transport layer, etc., is formed by application of ink containing functional material by a coating method such as an inkjet method. Inkjet methods include, for example, dropping ink into an opening provided in a bank, then forming a functional layer by drying the ink.
Film thickness of the functional layer is preferably uniform, and in a case where film thickness is not uniform, uneven luminance can occur. However, when the opening in the bank into which ink is dropped has a shape that has a long axis and a short axis, an effect occurs such that film thickness of a central portion of the functional layer in a direction of the long axis becomes thicker than film thickness of end portions of the functional layer in the direction of the long axis.
As one method of suppressing such an effect, making liquid repellency of surfaces of central sections in the direction of the long axis of an inclined portion of a bank greater than liquid repellency of surfaces of end sections in the direction of the long axis of the inclined portion of the bank is disclosed in patent literature 1. Specifically, a method is disclosed in which liquid repellency of a surface is reduced by irradiating with ultraviolet light only the end sections of the inclined portion, thereby making liquid repellency of the central sections of the inclined portion greater than the liquid repellency of the end sections.